Installation and method for producing cold or heat using a sorption system

ABSTRACT

A method and installation is described for producing cold and/or heat, in a place where the latter are to be used, from one or more heat energy sources. The method is carried out in an installation comprising two or three assemblies of two reactors in which reversible phenomena involving a gas take place, said phenomena being exothermic in the sense of synthesis and endothermic in the sense of decomposition. The energy for the operation of the installation is supplied by a low temperature reactor of one or two assemblies. The installation is suitable for the remote production of cold or heat by means of the transport of gas at ambient temperature.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an installation and a method forproducing cold and/or heat by a sorption system.

2. Description of the Related Art

When the production of energy is not located near the place where theenergy is required, it is necessary to provide for transport means. Themost widespread energy transport means are the electricity distributiongrids. It is nonetheless well-known on the one hand that the conversionefficiency of a primary energy into electricity barely exceeds 50%, andthat furthermore, the transport of the electricity is accompanied bylosses of about 15%. It is also known how to transport energy in thermalform for the distribution of cold or heat, particularly in urban orindustrial networks, using heat transfer fluids (such as water or steamfor example) which exchange heat with the medium to be heated or to becooled. In most cases, these types of exchange involve an exchange ofsensible heat or latent heat, which causes the recirculation of largefluid flows and consequently heat losses associated with the high or lowtemperature of the heat transfer fluid, as well as a high consumption ofpumping energy.

Installations for producing heat or cold are known based onthermochemical systems, which employ reversible processes between a gas,called the working gas, and a liquid or a solid. In these systems, thecombination step between the gas and the liquid or the solid (absorptionof the gas by the liquid, adsorption of the gas on the solid, reactionbetween the gas and the solid) is exothermic, and the reverse step isendothermic. A large number of reactors and methods based on theseprinciples have been described. They are described in particular in U.S.Pat. No. 4,531,374 (Alefeld) which describes many variants of a devicefor producing cold or heat based on reversible reactions. These devicesoperate by reversible absorption of a working gas by a liquid in twoworking gas circulation circuits operating at two or three pressurelevels. Owing to the various operating modes described, the use of sucha reactor requires the circulation of the liquid absorbent between oneof the reactors of one of the working gas circulation circuits and oneof the reactors of the other circuit. This circulation of largequantities of liquid demands pumping means which consume non-negligiblequantities of energy, and considerable insulation means to prevent heatlosses during the transport of the liquid. The energy supplied to thedevice during a complete operating cycle is added sometimes to theevaporator supplying the working gas, sometimes to the reactorcontaining the liquid enriched in gas, in order to liberate the gas,said input therefore taking place at temperatures higher than the gasevaporation temperature and consequently incurring a higher cost.Furthermore, U.S. Pat. No. 4,523,635 and U.S. Pat. No. 4,623,018describe systems which operate by reversible insertion of hydrogen inhydrides. The systems comprise at least two operating units eachconsisting of two reactors containing a hydride and connected by a pipefor circulating hydrogen. According to U.S. Pat. No. 4,523,635, duringan operating cycle, hydrogen is liberated from a first hydride by addingheat at high temperature to the reactor of one operating unit whichcontains the hydride whereof the equilibrium temperature is the higher.In the operating mode described in U.S. Pat. No. 4,623,018, each cycleincludes at least one step during which heat is added by an externalsource to a “high temperature” reactor of one of the operating units.

SUMMARY OF THE INVENTION

The present invention is aimed at supplying a method and an installationfor producing cold and/or heat at their place of use, using one or aplurality of thermal energy sources, thereby avoiding the transportationof liquid or solid material, and by supplying the energy necessary forthe operation of the installation at a relatively low temperature.

An installation for producing cold and/or heat according to the presentinvention comprises an HP assembly comprising reactors R₁ and R′₁, an LPassembly comprising reactors R₃ and R′₃ and possibly an IP assemblycomprising reactors R₂ and R′₂. In the rest of the text, R_(i) denotesany one of the reactors R₁,R₂ and R₃, and R′_(i) denotes any one of thereactors R′₁, R′₂ and R′₃. The installation is characterized in that:

-   -   each reactor R_(i) is the seat of a reversible sorption        alternatively producing and consuming the gas G_(i),    -   each reactor R′_(i) is the seat of a reversible process        alternatively producing and consuming the gas G_(i),    -   the reactants in the reactors are selected so that, at a given        pressure: the sorption equilibrium temperature in the reactor        R_(i) of an assembly is higher than the equilibrium temperature        of the reversible process in the reactor R′_(i) of the same        assembly, the sorption equilibrium temperature in the reactor R₁        is lower than that in R₃, and, if applicable, the sorption        equilibrium temperature in R₂ is between the equilibrium        temperatures in R₁ and R₃,    -   the reactors R_(i) and R′_(i) of an assembly are equipped with        means for exchanging the gas G_(i),    -   the reactors R_(i) are equipped with means for exchanging heat        with each other,    -   the reactors are isolated from atmospheric pressure.

A Clapeyron diagram shows the equilibrium curve (pressure P, temperatureT) of a reversible process, generally in the form lnP=f(−1/T). Thetheoretical equilibrium curve is a line for a monovariant process suchas a chemical reaction or a liquid/gas phase change. The equilibriumcurve is a network of isosteres for the bivariant processes such as theadsorption of a gas on a solid or the absorption of a gas in a liquid,because the equilibrium point varies as a function of the concentrationof gas in the solid or the liquid. Owing to the representation used, acurve corresponding to a given reversible process situated further tothe left in a Clapeyron diagram means that, at a given pressure, thetransformation temperature is lower than that of a reversible processwhereof the equilibrium curve is situated further to the right in thediagram. In a given assembly of the installation of the invention, thetemperature in the reactor R′_(i) is consequently lower than thetemperature in the reactor R_(i) when the two reactors are caused tocommunicate by opening the gas transfer means, that is, when thereactors are at the same pressure.

In an installation according to the invention, the reactors R₁,R′₁ ofthe HP assembly consequently operate in a range of (pressure,temperature) (PT)₁ located at a roughly higher level than the range(PT)₃ of the LP assembly. The IP assembly, when the installationcomprises three assemblies, operates in a range (PT)₂ intermediatebetween (PT)₁ and (PT)₃.

The reversible processes in the reactors R′_(i) can be selected amongthe liquid/gas phase changes and among the reversible sorptions such asreversible chemical reactions, adsorptions of a gas on a solid,absorptions of a gas by a liquid, the formation of clathrate hydrates.

Each reactor R_(i) is the seat of a reversible sorption such as achemical reaction, an adsorption of a gas by a solid, an absorption of agas by a liquid, or the formation of clathrate hydrates.

A liquid/gas phase change Li⇄G_(i) is exothermic in the condensationdirection and endothermic in the evaporation direction. A reversiblesorption between a liquid or solid sorbent and a gas, which can bewritten Bi+G_(i)⇄(Bi,G_(i)), is exothermic in the sorption directionS_(i) and endothermic in the desorption direction D_(i).

Numerous combinations are possible based on these reversible processes,and they serve to reach desired temperatures for producing useful coldor useful heat.

For example, in the installations comprising two HP and LP assemblies,an identical reversible process or different processes can be used inthe reactors R′_(i). If the processes in the two reactors R′_(i)liberate the same gas, the sorbents in the reactors R_(i) must bedifferent. If the processes in the reactors R′i liberate differentgases, the sorbents in the reactors R_(i) may be identical or different.

Similarly, in the installations comprising three HP, LP and IPassemblies, reversible processes liberating the same gas G or liberatingdifferent gases G_(i) can be used in the reactors R′_(i). The reactorsR_(i) associated with reactors R′_(i) which liberate the same gas mustcontain different sorbents. When the reactors R′_(i) liberate differentgases, the reactors R_(i) associated with them may contain identical ordifferent sorbents.

In a specific embodiment, the reactors R′_(i) are the seat of aliquid/gas phase change liberating the same gas and each reactor R_(i)is the seat of a reversible sorption between said gas and a differentliquid or solid.

In another embodiment, each reactor R′_(i) is the seat of a liquid/gasphase change producing a different gas and each reactor is the seat of asorption involving a different solid or liquid.

The method according to the present invention for producing cold and/orheat in a given place comprises a succession of reversible processesbetween a gas and a liquid or a solid. It is characterized in that:

-   it is put into practice in an installation which comprises an HP    assembly comprising reactors R₁ and R′₁, an LP assembly comprising    reactors R₃ and R′₃ and possibly an IP assembly comprising reactors    R₂ and R′₂, in which installation:    -   each reactor R_(i) is the seat of a reversible sorption        alternatively producing and consuming the gas G_(i),    -   each reactor R′_(i) is the seat of a reversible process        alternatively producing and consuming the gas G_(i),    -   the respective sorbents and gases in the reactors are selected        so that, at a given pressure: the sorption equilibrium        temperature in the reactor R_(i) of an assembly is higher than        the equilibrium temperature of the reversible process in the        reactor R′_(i) of the same assembly, the sorption equilibrium        temperature in the reactor R₁ is lower than that in R₃, and, if        applicable, the sorption equilibrium temperature in R₂ is        between the equilibrium temperatures in R₁ and R₃,    -   the reactors R_(i) and R′_(i) of an assembly are equipped with        means for exchanging the gas G_(i),    -   the reactors R_(i) are equipped with means for exchanging heat        with each other,    -   the reactors are isolated from atmospheric pressure,-   the thermal energy sources necessary for the operation of the    installation supply the reactors R′_(i).

More specifically, the method for producing cold or heat according tothe invention comprises:

-   -   a preliminary step in which the gas exchange means between two        reactors of an assembly are closed and the respective sorbents        and gases are placed at ordinary temperature in the reactors so        that the reactor R₁ of the HP assembly contains the sorbent in a        form rich in gas (B1,G₁), the reactor R′₁ is in a state to        consume the gas G₁, the reactor R₃ of the LP assembly contains        the sorbent in a form poor in gas B3 and the corresponding        reactor R′₃ is in a state to supply gas G₃,    -   a step a) of the production of cold and or heat, during which        the gas exchange means are opened between the reactors R₃ and        R′₃ on the one hand, the reactors R₁ and R′₁, and if applicable        between the reactors R₂ and R′₂, possibly after having raised        the reactor R′₃ and if applicable R′₂ to a temperature higher        than the normal temperature by the input of heat energy,    -   a step b) of regeneration during which the gas exchange means        are opened between the reactors R₃ and R′₃ on the one hand, the        reactors R₁ and R′₁, and if applicable between the reactors R₂        and R′₂, after having raised the reactor R′₁ and if applicable        R′₂ to a temperature higher than the normal temperature by the        input of heat energy.

At the end of the regeneration step, the installation is again in astate to produce cold or heat. It then suffices to close the gasexchange means between the reactors of the same level, to maintain theinstallation in this state as long as necessary. If it is again desiredto produce cold or heat, it suffices to repeat step a) of productiondescribed here above, followed by the regeneration step b), and so forthas required.

In a specific embodiment, essentially aimed to produce cold, the methodof the invention is characterized in that:

-   -   the respective gases and sorbents in the LP assembly (or the LP        and IP assemblies) are selected so that, at the respective        pressure which occurs in R′₃ (or in R′₃ and R′₂) after opening        the gas exchange means in the reactors, the equilibrium        temperature of the reversible process in R′₃ (or in R′₃ and in        R′₂) corresponds to the temperature at which the production of        cold is desired,    -   during step a) of production, the gas exchange means are opened        between the reactors without a prior input of heat energy to the        reactor R′₃ (or to the reactors R′₃ and R′₂).

In an installation according to the invention used to produce cold, thecold production temperature is determined by the temperature at whichthe gas G_(i) is liberated in the reactor R′_(i) of the LP assembly orof the LP and IP assemblies which are in the lowest ranges of (pressure,temperature). The reversible processes in the two reactors of an LPassembly (and possibly of the IP assembly) are selected so that thesimple communication of the reactors R_(i) and R′_(i) of the sameassembly causes the spontaneous endothermic liberation of the gas G_(i)in R′_(i) and the sorption phase in R_(i), with the withdrawal of theheat energy necessary from the ambient medium, that is the production ofcold at the level of R′_(i). The spontaneous withdrawal of heat energyfrom the ambient medium results in the production of cold in the reactorR′₃ and if applicable in the reactor R′₂ during step a). Then, toregenerate the installation during step b), heat energy is added via thereactor R′_(i) of the assembly having the highest range (pressuretemperature), and possibly of the assembly having the intermediate range(pressure, temperature), before opening the gas exchange means betweenthe reactors R_(i) and R′_(i). Simultaneously, the installation restoresheat energy during each of the steps, to the reactors R′_(i) which arenot involved by the introduction of energy and which are accordingly atintermediate temperatures between the low cold production temperaturesand the high regeneration temperatures of the installation. If theseintermediate temperatures are useful temperatures, the installation canbe used to produce cold and heat simultaneously.

In an installation according to the invention comprising two HP and LPassemblies, the cold is produced at the temperature at which the gas isliberated in the reactor R′₃ of the LP assembly. The method is put intopractice in the following conditions:

-   during a preliminary step,    -   the gas transfer means between R₁ and R′₁ on the one hand,        between R₃ and R′₃ on the other are closed,    -   the respective sorbents and gases are introduced into the        reactors so that the reactor R₁ of the HP assembly contains the        sorbent in a form rich in gas (B1,G₂), the reactor R′₁ is in a        state to consume the gas G₁, the reactor R₃ of the LP assembly        contains the sorbent in a form poor in gas B3 and the        corresponding reactor R′₃ is in a state to supply gas G₃,    -   the respective gases and sorbents in the LP assembly are        selected so that, at the respective pressure which occurs in R′₃        after opening the gas exchange means, the equilibrium        temperature of the reversible process in R′₃ corresponds to the        temperature at which the production of cold is desired;-   during step a) which is the cold production step, the gas transfer    means are opened between the reactors R₃ and R′₃ on the one hand and    between the reactors R₁ and R′₁ on the other, thereby causing the    spontaneous liberation of gas G₃ in R′₃, the exothermic sorption of    G₃ with the sorbent B3 in R₃, the endothermic desorption of the    sorbent rich in gas (B1,G₁) in R₁, the exothermic consumption of the    gas G₁ in R′₁;-   during step b) which is the regeneration step, heat energy is added    to R′₁ to raise it to a temperature higher than the ambient    temperature, the gas transfer means are opened between the reactors    R₃ and R′₃ on the one hand and between the reactors R₁ and R′₁ on    the other, thereby causing the liberation of gas G₁ in R′₁, the    exothermic sorption of G₁ with the sorbent B1 in R₁, the endothermic    desorption of the sorbent rich in gas (B3,G3) in R₃, the exothermic    consumption of the gas G3 in R′₃.

At the end of step b), the installation is again in a state to producecold. It suffices to connect the reactors R₃ and R′₃ of the LP assembly.In such an installation, the cold is produced in R′₃ and regeneration isachieved by R′₁. Only the reactor R′₃, the seat of cold production, isnecessarily located at the place where the production of cold isrequired. The reactor R′₁ supplied with heat energy during theregeneration of the installation is located at the place where the heatenergy is available and the other reactors are located at anyappropriate place, that is, at any distance from the place of coldproduction. It is therefore possible to produce cold in a given placefrom a heat energy source located elsewhere, by the simple circulationof gas at any temperature, without the transport of hot or cold liquidor solid. All the difficulties connected with the actual transport ofsolids or gases are thereby eliminated, as well as the heat losses.

The operation of an installation with two assemblies as described hereabove is similar, whether the respective gases G₁ and G₃ are identicalor different.

In an installation comprising three assemblies, several cold productionmodes can be considered. The cold can be produced at two differenttemperatures during the same production cycle. The cold can be producedat a given temperature in two successive phases during the productionstep a). The cold can also be produced at a given temperature in asingle phase during the step a), the regeneration step then taking placein two phases.

For the production of cold at two different temperatures, the method isput into practice in an installation which comprises three HP, LP and IPassemblies respectively comprising the reactors R₁,R′₁, R₃,R′₃ andR₂,R′₂, in the following conditions:

-   during a preliminary step,    -   the gas exchange means are closed between the reactors R₁,R′₁,        R₃,R′₃ and R₂,R′₂,    -   the respective sorbents and gases are introduced into the        reactors so that the reactor R₁ of the HP assembly contains the        sorbent in a form rich in gas (B1,G₁), the reactor R′₁ is in a        state to consume the gas G₁, the reactors R₃ and R₂ of the LP        and IP assemblies contain their sorbent in a form poor in gas,        respectively B3 and B2, and the reactors R′₃ and R′₂ are in a        state to supply the respective gases G₃ and G₂,    -   the respective gases and sorbents in the LP and IP assemblies        are selected so that, at the respective pressures which occur in        R′₃ and R′₂ after opening the gas exchange means, the        equilibrium temperatures of the respective reversible processes        in R′₂ and R′₃ correspond to the temperatures at which the        production of cold is desired;-   during step a) the gas exchange means are opened between the    reactors R₁,R′₁, R₃,R′₃ and R₂,R′₂, thereby causing the spontaneous    liberation of G₃ in R′₃ and of G₂ in R′₂, the exothermic sorption of    G₃ with the sorbent B3 in R₃, the exothermic sorption of G₂ with the    sorbent B2 in R₂, the endothermic desorption of the sorbent rich in    gas (B1,G₁) in R₁, the exothermic consumption of the gas G₁ in R′₁;-   during step b), heat energy is added to R′₁, the gas exchange means    are then opened between the reactors R₁,R′₁,R₃,R′₃ and R₂,R′₂,    thereby causing the liberation of gas G₁ in R′₁, the exothermic    sorption of G₁ with the sorbent B1 in R₁, the endothermic desorption    of the sorbent rich in gas (B3,G₃) in R₃, the exothermic consumption    of the gas G₃ in R′₃, the endothermic desorption of the sorbent rich    in gas (B2,2) in R₂, and the exothermic consumption of the gas G2 in    R′₂.

During step a), the production of cold is observed in R′₃ and R′₂.During step b), the installation is regenerated by supplying heat energyto R′₁. Cold can thereby be produced by the simple circulation of gas atan ordinary temperature, at the place where R′₃ and R′₂ are located, theother portions of the installation and the heat source supplying R′₁being situated elsewhere.

For the production of cold in two phases during the cold productionstep, the method is put into practice in an installation which comprisesthree HP, LP and IP assemblies respectively comprising the reactorsR₁,R′₁, R₃,R′₃ and R₂,R′₂, in the following conditions:

-   during a preliminary step,    -   the gas exchange means are closed between the reactors R₁,R′₁,        R₃,R′₃ and R₂,R′₂,    -   the respective sorbents and gases selected are introduced in the        reactors so that the reactors R₁ and R₂ contain their respective        sorbent in a form rich in gas (B1,G₁) and (B2,G₂), the reactors        R′₁ and R′₂ are in a state to consume the respective gas G₁ and        G₂, the reactor R₃ contains the sorbent in a form poor in gas        B3, and the reactor R′₃ is in a state to supply the gas;-   during step a) in a first phase, the gas exchange means are opened    between the reactors R₃, R′₃ on the one hand and the reactors R₂,R′₂    on the other, thereby causing the spontaneous liberation of G₃ in    R′₃ with the production of cold, the exothermic sorption of G₃ with    the sorbent B3 in R₃, the endothermic desorption of the sorbent rich    in gas (B2,G₂) in R₂, the exothermic consumption of G₂ in R′₂; in a    second phase, the gas exchange means are opened between the reactors    R₁,R′₁ on the one hand and the reactors R₂,R′₂ on the other, thereby    causing the spontaneous liberation of G₂ in R′₂ with the production    of cold, the exothermic sorption of G₂ with the sorbent B2 in R₂,    the endothermic desorption of the sorbent rich in gas (B1,G₁) in R₁,    the exothermic consumption of the gas G₁ in R′₁;-   during step b), heat energy is added to R′₁ to raise it to a    temperature higher than the normal temperature, the gas transfer    means are then opened between the reactors R₁,R′₁ on the one hand    and the reactors R₃,R′₃ on the other, thereby causing the liberation    of gas G₁, the exothermic sorption of G₁ with the sorbent B1 in R₁,    the endothermic desorption of the sorbent rich in gas (B3,G₃) in R₃,    and the exothermic consumption of the gas G₃ in R′₃.

At the end of the step b), the installation is again in a state toproduce cold. The simple contacting of R′₃ and R₃ serves to restart theprocess. In this specific case, the reactors R′₃ and R′₂ can be locatedat the same place or in different places, depending on whether cold isto be produced in one or two places, using a heat source supplying thereactor R′₁ located elsewhere. All or some of the gases may be identicalin the installation. If the reactors R′₃ and R′₂ are the seat of thesame reversible process involving the same gas, the cold is produced atthe same temperature in the two phases of the production phase. Thisembodiment enables an increase in the cold production efficiency.

For the production of cold in a phase during the cold production step,the method is put into practice in an installation which comprises threeHP, LP and IP assemblies respectively comprising the reactors R₁,R′₁,R₃,R′₃ and R₂,R′₂,in the following conditions:

-   during a preliminary step,    -   the gas exchange means are closed between the reactors R₁,R′₁,        R₃,R′₃ and R₂,R′₂,    -   the respective sorbents and gases are introduced into the        reactors R_(i) and the reactors R′_(i) and selected so that the        reactors R₁ and R₂ contain their respective sorbent in a form        rich in gas (B1,G₁) and (B2,G₂), the reactors R′₁ and R′₂ are in        a state to consume the respective gas G₁ and G₂, the reactor R₃        contains the sorbent in a form poor in gas B3, and the reactor        R′₃ is in a state to supply the gas;-   during step a) the gas transfer means are opened between the    reactors R₃,R′₃ on the one hand and the reactors R₁,R′₁ on the    other, thereby causing the spontaneous liberation of G₃ in R′₃, the    exothermic sorption of G₃ with the sorbent B3 in R₃, the endothermic    desorption of the sorbent rich in gas (B1,G₁) in R₁, the exothermic    consumption of the gas G₁ in R′₁;-   during step b), in a first phase, heat energy is added to R′₁ and    the reactors R₁,R′₁ on the one hand and the reactors R₂,R′₂ on the    other are connected, thereby causing the spontaneous liberation of    G₁, the exothermic sorption of G₁ with the sorbent B1 in R₁, the    endothermic desorption of the sorbent rich in gas (B2,G₂) in R₂, and    the exothermic consumption of the gas G₂ in R′₂; in a second phase,    heat energy is added to R′₂, the reactors R₂,R′₂ on the one hand and    the reactors R₃,R′₃ on the other are connected, thereby causing the    liberation of gas G₂, the exothermic sorption of G₂ with the sorbent    B2 in R₂, the endothermic desorption of the sorbent rich in gas    (B3,G₃) in R₃, and the exothermic consumption of the gas G₃ in R′₃.

This embodiment, in which the cold is produced in the reactor R′₃ usingenergy sources supplying the reactors R′₁ and R′₂ placed elsewhere,serves to increase the cold production capacity.

It therefore appears that, in all the embodiments of the method of theinvention for producing cold, the cold is produced in the reactor R′₃ inan installation with two assemblies which is regenerated by the input ofheat to the reactor R′₁, or in the reactor R′₃ (or the reactors R′₃ andR′₂) in an installation with three assemblies which is regenerated bythe input of heat in the reactors R′₂ and R′₁ (or in the reactor R′₁).In all cases, the heat source or sources used for the regeneration ofthe installation may be placed at a certain distance from the placewhere the cold is to be produced. Cold can thereby be produced at agiven place, using an energy source placed elsewhere, by the simpletransport of the working gas at ambient temperature. Thischaracteristic, combined with the input of heat to the low temperaturereactors of an assembly, therefore allows the remote production of coldand in a more economical manner than in the installations of the priorart.

In another embodiment, essentially aimed to produce heat at a givenplace of use, at a temperature higher than the temperature of a heatenergy source, the method of the invention is characterized in that,during step a) of production, heat energy is added to the installationby the reactor R′₃, and possibly by the reactor R′₂, before opening thegas exchange means between the reactors R₃ and R′₃, and possibly betweenthe reactors R₂ and R′₂.

In an installation according to the invention aimed to produce heat at atemperature higher than that of the energy source employed, during stepa) of production, heat energy is supplied to the installation by thereactor R′₃ of the LP assembly or by the reactors R′₃ and R′₂ of the LPand IP assemblies, and heat is recovered in the reactor R′₁ of the HPassembly or by the reactors R′₁ and R′₂ of the HP and IP assemblies,that is, at the elevated operating temperature of the HP assembly and ifapplicable of the IP assembly. The temperature at which the heat isproduced is determined by the temperature at which the gas G₁ isconsumed in the reactor R′₁ and if applicable the temperature at whichthe gas G₂ is consumed in the reactor R′₂. In step b) of regeneration,the heat is supplied to the reactor R′₁ and if applicable to R′₂, at atemperature similar to that of the source of step a), and degraded heatis recovered in the reactor R′₃ and if applicable in R′₂. Thetemperature at which the heat is introduced into R′₁ and possibly intoR′₂ in the regeneration step may be lower than the temperature at whichthe heat is introduced into R′₃ during the production step.

The heat Q produced at elevated temperature t in reactor R′₁ (andpossibly R′₂) can be used for example in a heat exchanger or in aprocess requiring heat at said elevated temperature t. This use releasesa certain quantity of heat Q′ at a lower temperature to such thatQ′=Q[1−(t₀/t)] corresponding to the exergy of the heat Q. This heat Q′can advantageously be used in step b) to initiate the regeneration ofthe installation. In this particular embodiment of the method of theinvention for producing heat, it is therefore unnecessary to dispose ofa heat source external to the installation to regenerate theinstallation, and the heat can be produced at elevated temperature inR′₁ (or R′₁ and R′₂) using one or a plurality of heat sources availableelsewhere at lower temperature.

For the production of heat at a given temperature, the method of theinvention is put into practice in an installation which comprises an HPassembly comprising the reactors R₁ and R′₁ and an LP assemblycomprising the reactors R₃ and R′₃, and it is characterized in that:

-   during a preliminary step:    -   the gas transfer means between R₁ and R′₁ on the one hand,        between R₃ and R′₃ on the other are closed,    -   the respective sorbents and gases are introduced into the        reactors so that the reactor R₁ of the HP assembly contains the        sorbent in a form rich in gas (B1,G₁), the reactor R′₁ is in a        state to consume the gas G₁, the reactor R₃ of the LP assembly        contains the sorbent in a form poor in gas B3 and the        corresponding reactor R′₃ is in a state to supply gas G₃,-   during step a) of the production of heat, heat energy is added to    R′₃ to raise it to a temperature higher than the normal temperature,    the gas transfer means are then opened between the reactors R₃ and    R′₃ on the one hand and the reactors R₁ and R′₁ on the other,    thereby causing the spontaneous liberation of gas G₃ in R′₃, the    exothermic sorption of G₃ with the sorbent B3 in R₃, the endothermic    desorption of the sorbent rich in gas (B1,G₁) in R₁, the exothermic    consumption of the gas G₁ in R′₁ with the production of heat;-   during step b), heat energy is added to R′₁ to raise it to a    temperature higher than the normal temperature, the gas transfer    means are then opened between the reactors R₃ and R′₃ on the one    hand, and the reactors R₁ and R′₁, thereby causing the liberation of    the gas G₁ in R′₁, the exothermic sorption of G₁ with the sorbent B1    in R₁, the endothermic desorption of the sorbent rich in gas (B3,G3)    in R₃, the exothermic consumption of the gas G3 in R′₃, and the    regeneration of the installation.

In view of the respective equilibrium curves of the reversible processesemployed in the different reactors, the heat energy introduced duringstep a) in R′₃ and during step b) in R′₁ is at an intermediatetemperature between the temperature at which heat is recovered in R′₁during step a), and the temperature at which the degraded heat isrecovered in R′₃ during step b).

In a specific embodiment, the method of the invention can be put intopractice to produce a quantity of heat at a given place at a temperaturehigher than that of two heat sources located at another place. In thiscase, the method of the invention is put into practice in aninstallation which comprises three HP, LP and IP assemblies,respectively comprising the reactors R₁,R′₁, R₃,R′₃ and R₂,R′₂, in thefollowing conditions:

-   during a preliminary step,    -   the gas exchange means are closed between the reactors R₁,R′₁,        R₃,R′₃ and R₂,R′₂,    -   the respective sorbents and gases selected are introduced into        the reactors so that the reactor R₁ contains the sorbent in a        form rich in gas (B1,G₁), the reactor R′₁ is in a state to        consume the gas G₁, the reactors R₃ and R₂ contain their        respective sorbent in a form poor in gas B3 and B2, and the        reactors R′₃ and R′₂ are in a state to supply the respective gas        G₃ and G₂;-   during step a), heat energy is supplied to R′₃ and R′₂ to raise them    to a temperature higher than the ambient temperature, the gas    exchange means are then opened between the reactors R₃,R′₃, the    reactors R₂,R′₂ and the reactors R₁,R′₁, thereby causing the    spontaneous liberation of G₃ in R′₃ and of G₂ in R′₂, the exothermic    sorption of G₃ with the sorbent B3 in R₃ and the exothermic sorption    of G₂ with the sorbent B2 in R₂, the endothermic desorption of the    sorbent rich in gas (B1,G₁) in R₁, the exothermic consumption of G₁    in R′₁ with the liberation of heat;-   during step b), heat energy is supplied to R′₁ to raise it to a    temperature higher than the normal temperature, the gas transfer    means are then opened between the reactors R₃,R′₃, the reactors    R₂,R′₂ and the reactors R₁,R′₁, thereby causing the liberation of    gas G₁ in R′₁, the exothermic sorption of G₁ with the sorbent B1 in    R₁, the endothermic desorption of the sorbent rich in gas (B3, G₃)    in R₃ and the sorbent rich in gas (B2,G₂) in R₂, and the exothermic    consumption of the gas G₃ in R′₃ and of the gas G₂ in R′₂.

In this embodiment, the heat introduced into the reactors R′₂ and R′₃ atan intermediate temperature is recovered in R′₁ at a higher temperatureduring the production step, and the heat introduced into R′₁ at anintermediate temperature is restored at a lower temperature during theregeneration step.

The method of the invention can furthermore produce heat in a phaseduring the production step, and regenerate the installation in twosuccessive phases. The method is then put into practice in aninstallation which comprises three HP, LP and IP assemblies respectivelycomprising the reactors R₁,R′₁, R₃,R′₃ and R₂,R′₂, in the followingconditions:

-   during a preliminary step    -   the gas transfer means are closed between the different        reactors,    -   the respective sorbents and gases are introduced into the        reactors, at normal temperature, so that R₁ and R₂ contain their        respective sorbent in the state rich in gas (S1,G₁) and (S2,G₂),        R₃ contains the sorbent in the state poor in gas, R′₁ and R′₂        are in a state to consume the gas G₁ and the gas G₂        respectively, and R′₃ is in a state to liberate the gas G₃;-   during step a), heat energy is introduced into R′₃, the gas transfer    means are then opened between the reactors R₃,R′₃ on the one hand    and the reactors R₁,R′₁ on the other, thereby causing the    spontaneous liberation of G₃ in R₃, the exothermic sorption of G₃    with the sorbent B3 in R₃, the endothermic desorption of the sorbent    rich in gas (B1,G₁) in R₁, the exothermic consumption of the gas G₁    in R′₁ with the production of heat at a higher temperature than that    of the source supplying R′₃;-   during step b), in a first phase, heat energy is introduced into    R′₁, the gas transfer means are then opened between the reactors    R₁,R′₁ on the one hand and the reactors R₂,R′₂ on the other, thereby    causing the spontaneous liberation of G₁, the exothermic sorption of    G₁ with the sorbent B1 in R₁, the endothermic desorption of the    sorbent rich in gas (B2,G₂) in R₂, and the exothermic consumption of    the gas G₂ in R′₂; in a second phase, heat energy is supplied to    R′₂, the gas transfer means are then opened between the reactors    R₂,R′₂ on the one hand and the reactors R₃,R′₃ on the other, thereby    causing the liberation of gas G₂, the exothermic sorption of G₂ with    the sorbent B2 in R₂, the endothermic desorption of the sorbent rich    in gas (B3,G₃) in R₃, and the exothermic consumption of the gas G₃    in R′₃.

The method of the invention furthermore serves to produce heat in twosuccessive phases during the production step, and to regenerate theinstallation in one phase. The method is then put into practice in aninstallation that comprises three HP, LP and IP assemblies respectivelycomprising the reactors R₁,R′₁, R₃,R′₃ and R₂,R′₂, in the followingconditions:

-   during a preliminary step:    -   the gas transfer means are closed between the different        reactors,    -   the respective sorbents and gases are introduced into the        reactors, at normal temperature, so that R₂ contains the sorbent        in the state rich in gas (S2,G₂), R₃ and R₁ contain their        sorbent in the state poor in gas with B3 and B1 respectively,        R′₂ is in a state to consume the gas G₂, and R′₃ and R′₁ are in        a state to liberate the gas G₃ and G₂ respectively;-   during step a) in a first phase, heat energy is introduced into R′₃,    the reactors R₃,R′₃ on the one hand and the reactors R₂,R′₂ on the    other are connected, thereby causing the spontaneous liberation of    G₃, the exothermic sorption of G₃ with the sorbent B3 in R₃, the    endothermic desorption of the sorbent rich in gas (B2,G₂) in R₂, the    exothermic consumption of G₂ in R′₂ with the production of heat at a    temperature higher than that of the source supplying R′₃; in a    second phase, heat energy is introduced into R′₂, the reactors    R₁,R′₁ on the one hand and the reactors R₂,R′₂ on the other are    connected, thereby causing the spontaneous liberation of G₂, the    exothermic sorption of G₂ with the sorbent B2 in R2, the endothermic    desorption of the sorbent rich in gas (B1,G₁) in R₁, the exothermic    consumption of the gas G₁ in R′₁ with the production of heat at a    temperature higher than that of the source supplying R′₂;-   during step b), heat energy is supplied to R′₁, the gas transfer    means are then opened between the reactors R₁,R′₁ on the one hand    and the reactors R₃,R′₃ on the other, thereby causing the liberation    of gas G₁, the exothermic sorption of G₁ with the sorbent B1 in R₁,    the endothermic desorption of the sorbent rich in gas (B3,G₃) in R₃,    and the exothermic consumption of the gas G in R′₃ with the    liberation of heat at a temperature lower than that of the energy    source supplying R′₁.

In each specific case of the production of heat, during step a), aquantity of heat is brought to a higher temperature and is utilized,whereas during step b), a quantity of heat is brought to a lowertemperature and consists of lost heat if the low temperature level isnot useful.

The present invention is described in greater detail with the help ofspecific examples of operation and by reference to the correspondingClapeyron diagrams. The description is based on reactors R′_(i) whichare the seat of a liquid/gas phase change alternately operating asevaporator and as condenser for a gas G_(i). The transposition toinstallations wherein the reactors R′_(i) are the seat of a monovariantor divariant sorption is within the scope of the person skilled in theart. In the case of a divariant sorption, the equilibrium line in thecorresponding reactor R′_(i) is a set of isosteres. In the diagrams, Eiand Ci respectively denote the evaporation and the condensation of thegas G_(i) in the reactor R′_(i).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the Clapeyron diagram of an installation according to theinvention comprising two assemblies operating with two solids and onegas for the production of cold.

FIG. 2 shows the Clapeyron diagram of an installation according to theinvention comprising two assemblies operating with two solids and twogases for the production of cold.

FIG. 3 shows the Clapeyron diagram of an installation according to theinvention comprising three assemblies operating with three solids andone gas for the production of cold.

FIG. 4 shows another Clapeyron diagram of an installation according tothe invention comprising three assemblies operating with three solidsand one gas for the production of cold.

FIG. 5 shows another Clapeyron diagram of an installation according tothe invention comprising three assemblies operating with three solidsand one gas for the production of cold.

FIG. 6 shows the Clapeyron diagram of an installation according to theinvention comprising three assemblies operating with one solid and threegases for the production of cold.

FIG. 7 shows the Clapeyron diagram of an installation according to theinvention comprising two assemblies operating with two solids and onegas for the production of heat.

FIG. 8 shows the Clapeyron diagram of an installation according to theinvention comprising two assemblies operating with two solids and twogases for the production of heat.

FIG. 9 shows the Clapeyron diagram of an installation according to theinvention comprising three assemblies operating with three solids andone gas for the production of heat.

FIG. 10 shows another Clapeyron diagram of an installation according tothe invention comprising three assemblies operating with three solidsand one gas for the production of heat.

FIG. 11 shows another Clapeyron diagram of an installation according tothe invention comprising three assemblies operating with three solidsand one gas for the production of heat.

FIG. 12 shows a specific case of a Clapeyron diagram of an installationaccording to the invention comprising two assemblies operating with onesolid, one liquid and one gas for the production of cold.

FIG. 13 shows a specific case of a Clapeyron diagram of an installationaccording to the invention comprising two assemblies operating with twosolids and one gas for the production of cold.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The production of cold in an installation comprising two HP and LPassemblies wherein the reactors R′₁ and R′₃ operate alternately asevaporator/condenser for the same gas G and the reactors R₁ and R₃contain different sorbents B1 and B3, is shown by the Clapeyron diagramshown in FIG. 1. The sorptions in the reactors R₁ and R₃ are monovariantprocesses. G, B1 and B3 are selected so that, at the respectiveoperating pressures, the sorption temperature S1 is higher than thedesorption temperature D3 and the exothermic sorption temperature S3 ishigher than the desorption temperature D1.

-   In the initial state, the reactors R′₁ and R′₃ contain the gas G in    liquid form, the reactor R₁ contains (B1,G) and the reactor R₃    contains B3; R₁ and R₃ are in thermal contact; the HP and LP    assemblies are isolated from the atmospheric pressure and in a    thermal relation with the ambient medium;-   during a first operating step, cold is produced at the temperature    T_(3B) in the following manner: R₁ is communicated with R′₁, and R₃    with R′₃; the HP assembly is placed at the pressure P_(1B) and the    LP assembly at the pressure P_(3B). The pressure and temperature    (P,T) conditions in which the reactors R′₃, R₃, R₁ and R′₁ are then    found are materialized respectively by E₃, S₃, D₁ and C₁ in the    diagram. Owing to the very great affinity between B₃ and C, a    spontaneous evaporation of G occurs in R′₃. The quantity of heat Q₃    required to evaporate the quantity of gas G necessary for the    sorption S3 is spontaneously withdrawn from the external medium,    thereby producing cold at the temperature T_(3B); simultaneously,    the quantity of heat Q′₃ liberated in R₃ by the sorption S3 is    transmitted to the content of R₁ and causes the desorption D1 by    liberating the gas G. Said gas G is transported to the reactor R′₁    operating as a condenser, where the release of a quantity of heat    Q″₃ at the temperature T_(1B) is observed;-   during a second step, the installation is regenerated: the gas    exchange means between the reactors of the same assembly being    closed, a quantity of heat Q₁ is introduced into the reactor R′₁ to    raise it to the temperature T_(1H), the reactors R₁,R′₁ on the one    hand and the reactors R₃ and R′₃ on the other are then placed in    communication. In the HP assembly, the pressure settles at the    equilibrium pressure P_(1H), causing the evaporation of G in R′₁,    the exothermic sorption S1 in R₁, the transfer of heat Q′₁ released    by the sorption S1 to R₃ to cause the desorption D₃, the liberation    of the gas G in R₃ and its condensation in R′₃ with the liberation    of a quantity of heat Q″₃ at the temperature T_(3H). The conditions    (P,T) in which the reactors R′₃, R₃, R₁ and R′₁ are then found are    materialized respectively by the points C₃, D₃, S₁ and E₁ in the    diagram. The installation is then again ready to produce cold. If    the reactor R₃ and the reactor R′₃ are isolated from each other at    this time, the installation stores potential cold. The cold can be    produced at any time by the simple communication of R₃ and R′₃ at    the pressure P_(3B).

It therefore appears that cold can be produced at the temperature T_(3B)at the place where R′₃ is located by supplying heat energy to a reactorR′₁ which may be installed elsewhere, and particularly in a place wherethe heat energy is readily available. If the temperatures T_(3H) andT_(1B) are useful temperature levels, the installation servessimultaneously to produce cold in R′₃ and heat in R′₁ during theso-called cold production step, and degraded heat in R′₃ during theregeneration step from the heat supplied to R′₁.

Cold is transported by the simple transport of the gas G in a pipeconnecting the reactor R₁ and the reactor R′₁ and in a pipe connectingthe reactor R₃ and the reactor R′₃ associated with it. The gas G and thesorbents B1 and B₃ used are selected as a function of the temperature atwhich the cold is to be produced, and the temperature of the heat energysource available.

The theoretical cold production efficiency of such an installation,which can be written η_(P)=Q₃/Q₁, is the ratio of the quantity of usefulheat Q₃ to the quantity of heat introduced. In practice, it is close to1.

The transport efficiency, which is defined by the ratio of the usefulproduction in a remote site (Q_(P3)) to the useful production made insitu (Q_(P1)), can be writtenη_(t) =Q _(P3) /Q _(P1) +W=1−(loss/Q _(P1) +W)where W is the gas pumping work. The transport of thermal energy with aninstallation according to the invention is not accompanied by heatlosses, because the energy is transported in chemical form, by a simplegas circulation.

Another embodiment of the invention for the production of cold, andpossibly of useful heat, is illustrated by FIG. 2. The installation issimilar to the one employed for the case shown in FIG. 1, as well as thesequence of successive steps. The difference resides in the fact thatthe HP assembly operates with a working gas G₁ and the LP assemblyoperates with a working gas G₃ different from G₁. In the initial state,the reactors R′₁ and R′₃ contain the respective gases G₁ and G₃ inliquid form, the reactor R₁ contains (B1,G₁) and the reactor R₃ containsB₃. As in the previous example, the pressure and temperature (P,T)conditions in which the reactors R′₃, R₃, R₁ and R′₁ are found arematerialized respectively by E₃, S₃, D₁ and C₁ in the diagram. Thismeans that, during the first operating step, the quantity Q₃ of coldproduced in R′₃ is at the temperature T_(3B) which is that of theevaporation of G₃ and the quantity of heat Q″₃ produced in the reactorR′₁ is at the temperature T_(1B) which is that of the condensation ofG₁. At the beginning of the second step, the conditions (P,T) in whichthe reactors R′₃, R₃, R₁ and R′₁ are found are materialized respectivelyby the points C₃, D₃, S₁, and E₁ in the diagram. During this secondstep, the quantity of heat Q₁ required to evaporate the quantity of gasG₁ necessary for the sorption S1 is introduced at the temperature T_(1H)which is that of evaporation of G₁ and the quantity of heat Q″₁liberated in R′₃ is at the temperature T_(3H) which is that of thecondensation of G₃.

FIG. 3 shows the Clapeyron diagram corresponding to an installationaccording to the invention which comprises three HP, LP and IPassemblies. In this specific case, the gas G is identical in the threereactors R_(i), and the sorbents Bi are all different. Such aninstallation allows many variants in the production of cold. Inparticular it allows the production of cold at two differenttemperatures, successively or simultaneously in the reactors R′₂ andR′₃, by the input of heat energy in R′₁ during the regeneration of theinstallation. The gas G and the sorbents Bi are selected so that, at therespective operating pressures, the temperatures of the sorptions S2 andS3 are substantially identical to each other and slightly higher thanthe temperature of the desorption D1, and so that the temperature of thesorption S1 is slightly higher than the temperatures of the desorptionsD2 and D3, said desorption temperatures being substantially identical.In the initial state, the three reactors R′_(i) contain the gas G inliquid form, the reactor R₁ contains the sorbent in a form rich in gas(B1,G) and the reactors R₂ and R₃ contain the sorbent in a form poor ingas, respectively B2 and B3; the reactors R_(i) and R′_(i) of anassembly are not in communication with each other; the reactors R_(i)are in thermal communication; the assemblies are isolated from theatmospheric pressure and are in thermal relation with the ambientmedium.

-   During a first operating step, cold is produced at the temperatures    T_(2B) and T_(3B) in the following manner: R₁ is communicated with    R′₁, R₂ with R′₂ and R₃ with R′₃; in view of the very great affinity    between B2 and G on the one hand, and B3 and G on the other, a    spontaneous evaporation of G occurs in R′₂ and in R′₃ (materialized    respectively by E₂ and E₃ in the figure). The quantity of heat    required to evaporate the quantity of gas G necessary for the    sorption S2 and the quantity of heat required to evaporate the    quantity of gas G necessary for the sorption S3 are withdrawn    spontaneously from the external medium, thereby producing cold at    the temperatures T_(2B) and T_(3B); simultaneously, the quantities    of heat liberated respectively in R₂ and in R₃ by the sorption are    transmitted to the content (B1,G) of R₁ and cause the desorption D2    by liberating the gas G. Said gas G is transported to the reactor    R′₁ operating as a condenser (denoted C1 in the figure), where a    release of heat at the temperature T_(iB) is observed;-   during a second step, the installation is regenerated, each of the    assemblies of reactors in the installation is at its high pressure    level P_(iH): a quantity of heat is introduced into R′₁ which    operates as an evaporator (denoted E₁ in the figure), said quantity    required to raise it to the temperature T_(1H), the two reactors of    each assembly are then communicated, thereby causing the evaporation    of gas G in R′₁, and the sorption S1 in R₁; the quantity of heat    released by the sorption is transmitted to the content of the    reactors R₂ and R₃ and causes the desorptions D2 and D3; the gas    liberated is transmitted to the reactors R′₂ and R′₃ in which it is    condensed by liberating heat (denoted respectively C₂ and C₃ in the    figure) respectively at the temperatures T_(3H) and T_(2H); at the    end of this step, the installation is again ready to supply cold. If    each of the reactors R₂ and R₃ is isolated from the respective    reactor R′₂ and R′₃ at this time, the installation stores potential    cold, which can be liberated at any time by the simple communication    of R₂ and R′₂ on the one hand and of R₃ and R′₃ on the other.

To produce cold selectively at the temperature T_(2B) or at thetemperature T_(3B), the first step is carried out by connecting thereactors R₁ and R′₁ on the one hand and, on the other, either thereactors R₃ and R′₃ in order to produce cold at T_(3B), or the reactorsR₂ and R′₂.

FIG. 4 shows the Clapeyron diagram corresponding to an installationaccording to the invention which comprises three assemblies of tworeactors. As in the previous case, the working gas G is identical in thethree reactors R_(i), and the sorbents Bi are all different. At thestart of the process, the reactor R₃ contains B3 and the other tworeactors respectively contain (B1,G) and (B2,G), and the whole system isat ambient temperature.

-   During a first step, R₃ is connected with R′₃ and R₂ is connected    with R′₂, thereby initiating the evaporation of G with the    production of cold at the temperature T_(3B), the sorption S3 in R₃    with the production of heat transmitted to (B2,G) contained in R₂,    which causes the desorption D2 and the liberation of gas G which    condenses in R′₂ with the liberation of heat at the temperature    T_(2H). The conditions (P,T) in which the reactors R′₃, R₃, R₂ and    R′₂ are found during this step are materialized respectively by the    points E₃, S₃, D₂ and C₂ in the diagram;-   during a second step, the production of cold is caused similarly at    R′₂ by the contacting of R₂ and R′₂ on the one hand and of R₁ and    R′₁ on the other, thereby causing the sorption S2 which supplies to    R₁ the heat necessary for the desorption D1 followed by the    production of heat at the temperature T_(1B) due to the condensation    in R′₁ of the liberated gas. The conditions (P,T) in which the    reactors R′₂, R₂, R₁ and R′₁ are found in this step are materialized    respectively by the points E₂, S₂, D₁ and C₁ in the diagram;-   during a third step, the system is regenerated by supplying heat to    R′₁ to raise it to the temperature T_(1H), and R₃ and R′₃ on the one    hand and R₁ and R′₁ on the other are then contacted, to liberate the    gas G in the direction of R₁ for the sorption S1. The heat liberated    is transferred in R₃ for the desorption D3 and the production of    heat in R′₃ by condensation of the liberated gas. The conditions    (P,T) in which the reactors R′₃, R₃, R₁ and R′₁ are found during    this step are materialized respectively by the points C₃, D₃, S₁ and    E₁ in the diagram. The installation is then ready for a new cold    production sequence.

The respective cold production temperatures T_(2B) and T_(3B) aresubstantially the same. It is therefore possible to produce a largequantity of cold, since it corresponds to two evaporation processes.

FIG. 5 shows the Clapeyron diagram corresponding to an installationaccording to the invention which comprises three assemblies of tworeactors. As in the previous case, the working gas G is identical in thethree reactors R_(i), and the sorbents Bi are all different. At thestart of the process, the reactor R₃ contains B3 and the other tworeactors contain (B1,G) and (B2,G) respectively, at ambient temperature.A difference from the previous examples resides in the fact that, duringthe cold production step, only the reactor R₃ operates in sorption modewith the production of cold in the reactor R′₃ at the temperatureT_(3B).

-   During a first step, the connection of R₃ and R′₃ and of R₁ and R′₁    causes the spontaneous evaporation of the gas G in R′ ₃. The    liberated gas G causes the sorption S3 with release of heat which is    transferred to R₁ to cause there the desorption D1, the condensation    of the gas liberated in R′₁ with the production of heat at the    temperature T_(1B);-   during a second step, heat is added to the reactor R′₁ to raise it    to the temperature T_(1H), R₁ and R′₁ are then contacted on the one    hand, R₂ and R′₂ on the other, with the effect of liberating the gas    G necessary for the sorption S1 in R₁, the heat released being    transferred to R₂ for the desorption D2 and the liberation of G    which condenses in R′₂ with the production of heat;-   during a third step, heat is added to R′₂ to raise it to the    temperature T_(2H), R₃ and R′₃ are then contacted on the one hand,    R₂ and R′₂ on the other, with the effect of liberating the gas G    necessary for the sorption S2 in R₂, the heat released being    transmitted to R₃ for the desorption of (B3,G) formed during the    previous step, so that the installation is regenerated for a new    cold production sequence at T_(3B).

This embodiment serves to produce cold at a very low temperature.

FIG. 6 shows the Clapeyron diagram corresponding to an installationsimilar to the one shown in FIG. 3 and operating in the same manner. Theonly difference resides in the fact that a different working gas is usedin each assembly. The cold is produced during a first step in thereactors R′₂ and R′₃ at the temperatures T_(2B) and T_(3B) and theinstallation is regenerated during a second step by adding heat energyto R′₁ operating as an evaporator at the elevated temperature T_(1H).

FIG. 7 shows the Clapeyron diagram corresponding to an installationaccording to the invention which is similar to the one used in theembodiment in FIG. 1 and which comprises two reactors R₁ and R₃ and twoassociated reactors R′₁ and R′₃, but operating to produce a quantity ofheat at a temperature higher than that of the source. In the initialstate, the reactors R′₁ and R′₃ contain the gas G in liquid form, thereactor R₁ contains (B1,G) and the reactor R₃ contains B3;

-   during a first operating step, heat is produced at the temperature    T_(1H) in the following manner: heat energy is added to R′₃ to raise    it to the temperature T_(3H), R₁ is then communicated with R′₁, and    R₃ with R′₃, causing the spontaneous evaporation of G in R′₃ with    the production of cold, the transfer of G in R₃ for the sorption S3,    the transfer of the heat liberated by the sorption to R₁ and the    desorption in R₁, the transfer of the gas liberated to R′₁ and    condensation with the liberation of heat at the temperature T_(iH);-   during a second step, the installation is regenerated, by adding    heat to R′₁ to raise it to the temperature T_(1B), then by    communicating the reactors of the same assembly, thereby causing the    evaporation of G in R′₁, the transfer of G to R₁, the exothermic    sorption in R₁, the transfer of the heat released to R₃, the    desorption in R₃, the transfer and the condensation of the gas to    R′₃ with the release of heat at a temperature lower than the ambient    temperature; the installation is then ready for a new heat    production step at a temperature level higher than that of the    source.

In this embodiment, heat can be produced at a given place using a heatsource located at another place, the heat being produced at atemperature level higher than that of the source, by simply transportinga gas in a pipe connecting the reactor R₁ and the reactor R′₁(evaporator/condenser in the present case) on the one hand, and thereactor R₃ and the evaporator/condenser R′₃ associated with it on theother. The working gas G and the sorbents B₁ and B₃ used are selected asa function of the temperature at which the heat is to be produced, andof the temperature of the heat energy source available.

Another embodiment of the invention for the production of heat is shownin FIG. 8. The installation is similar to the one employed for the caseshown in FIG. 7, as well as the sequence of successive steps. Thedifference resides in the fact that the gases G₁ and G₃ are different.In the initial state, the reactors R′₁ and R′₃ contain the respectivegases G₁ and G₃ in liquid form, the reactor R₁ contains (B1,G₁) and thereactor R₃ contains B₃. This means that, during the first operatingstep, the quantity of useful heat is produced in R′₁ at the temperatureT_(1H) which is that of the condensation of G₁ and during the secondregeneration step, the quantity of degraded heat recovered in R′₃ is atthe temperature T_(3B) which is that of the condensation of G₃.

FIG. 9 shows the Clapeyron diagram corresponding to the production ofheat in an installation similar to the one used for the production ofcold in the example shown in FIG. 3.

At the beginning of the process, the reactors R₂ and R₃ contain B2 andB3 respectively, the reactor R₁ contains (B1,G), and the correspondingreactors R′_(i) contain the gas G in its liquid form.

-   In a first step, sufficient quantities of heat are introduced    respectively in R′₂ and R′₃, said quantities being necessary to    raise them to the respective temperatures T_(2H) and T_(3H) which    are higher than the ambient temperature, and the reactors of each    assembly are then communicated. The gas G evaporates spontaneously    in R′₂ and R′₃, causing the sorptions S2 and S3. The heat released    during each sorption is transmitted to the reactor R₁ for the    desorption D1 which liberates gas G which condenses in R′₁,    producing useful heat at the temperature T_(1H);-   in a second step, heat is introduced into R′₁ to raise it to the    temperature T_(1B), and the reactors of each assembly are then    communicated. The gas G evaporates spontaneously in R′₁ causing the    sorption S1; the heat released by S1 is transmitted to R₂ and R₃,    causing the desorptions D2 and D3, so that the installation is again    in a state to produce heat. If the reactors R′₂ and R₂ on the one    hand, and R′₃ and R₃ on the other, are not connected, the heat is    stored. Since storage takes place in chemical form, there are no    heat losses.

FIG. 10 shows the Clapeyron diagram corresponding to an installationaccording to the invention which comprises three HP, LP and IPassemblies. The working gas G is identical in the three reactors R_(i),and the sorbents Bi are all different. The production of useful heattakes place in R′₁ operating as a condenser at its highest pressurelevel, thereby corresponding to the highest temperature of theinstallation. The installation is regenerated in two steps by theintroduction of heat at an intermediate temperature level.

At the start of the process, the reactor R₃ contains B3 and the othertwo reactors contain (B1,G) and (B2,G) respectively, at ambienttemperature.

-   During a first step, heat is introduced into R′₃ to raise it to the    temperature T_(3H) higher than the ambient temperature, R₃ and R′₃    are then communicated on the one hand, and R₁ and R′₁ on the other;    the spontaneous evaporation of G in R′₃ causes the sorption S3 in R₃    with the production of heat transmitted to (B1,G) contained in R₁,    then the desorption D1 and the liberation of gas G which condenses    in R′₁ with the liberation of heat at the temperature T_(1H) higher    than T_(3H);-   during a second step, heat is introduced into R′₁ to raise it to a    temperature T_(1B) higher than the ambient temperature, R₂ and R′₂    are then communicated on the one hand, and R₁ and R′₁ on the other;    the spontaneous liberation of G in R′₁ causes the sorption S1 which    supplies to R₂ the heat necessary for the desorption D2, and the    condensation of G in R′₂;-   during a third step, heat is supplied to R′₂, R₂ and R′₂ are then    communicated on the one hand, and R′₃ and R₃ on the other, to    liberate the gas G in the direction of R₂ for the sorption S2. The    heat liberated is transferred in R₃ for the desorption D3. The    installation is then ready for a new heat production sequence.

In this embodiment, the installation according to the invention producesheat utilized at a high level during the first step, and regenerationtakes place during the 2^(nd) and 3^(rd) steps.

FIG. 11 shows the Clapeyron diagram corresponding to an installationaccording to the invention which comprises three HP, LP and IPassemblies. The working gas G is identical in the three reactors R_(i),and the sorbents Bi are all different.

At the start of the process, the reactor R₃ contains B3 and the othertwo reactors contain (B1,G) and (B2,G) respectively.

-   During a first step, heat is introduced into R′₃, the heat necessary    to raise it to the temperature T_(3H), R₃ and R′₃ are then    communicated on the one hand, and R₂ and R′₂ on the other; the    evaporation of G in R′₃ causes the sorption S3 in R₃ with the    production of heat transmitted to (B2,G) contained in R₂, then the    desorption D2 and the liberation of gas G which condenses in R′₂    with the liberation of heat at the temperature T_(2H);-   during a second step, R′₂ is raised to the temperature T_(2H), R₂    and R′₂ are then communicated on the one hand, and R₁ and R′₁ on the    other, causing the sorption S2 which supplies to R₁ the heat    necessary for the desorption D1; the liberated gas condenses in R₁    while liberating heat at the temperature T_(1H);-   during a third step, heat is supplied to R′₁ to raise it to the    temperature T_(1B), R₁ and R′₁ are then communicated on the one    hand, and R′₃ and R₃ on the other to liberate the gas G in the    direction of R₁ for the sorption S1. The heat liberated is    transferred in R₁ for the desorption D3. The installation is then    ready for a new heat production sequence.

In this embodiment of the installation with three assemblies accordingto the invention, the heat is produced at an elevated temperature levelduring the first two steps of the operating cycle, and the installationis regenerated during the third step.

FIG. 12 shows the theoretical Clapeyron diagram of a specificinstallation comprising two assemblies operating for the production ofcold. In the two assemblies, the working gas is ammonia and the reactorsR′₁ and R′₃ consequently operate alternatively as a condenser and anevaporator of NH₃. In the HP assembly, the reactor R₁ is the seat of areaction of NH₃ with CaCl₂. In the LP assembly, the reactor is the seatof a reversible absorption of NH₃ by water according to the equationNH₃+H₂O.x₁NH₃⇄H₂O.x₂NH₃where x₁=0.1 and x₂=0.2. Since the process is bi-variant, theequilibrium line shifts as a function of the quantity of NH₃ absorbed.During the startup of such an installation, CaCl₂ is in a gas rich formand the water is poor in gas. The connecting of the reactors R′₃ and R₃places them at a pressure of about 4 bar, causing the evaporation of NH₃at 0° C. and the absorption of NH₃ by the water at an initialtemperature of 90° C. As the water is enriched with ammonia, thetemperature decreases in R₃ to the value of 80° C. when the ammoniacontent x in the water reaches 0.2. At the same time, the heat liberatedby the absorption of ammonia in the water is transmitted to the reactorR₁ to decompose the calcium chloride rich in ammonia. The liberatedammonia condenses in R′₁ at 40° C. while liberating heat. To regeneratethe installation, heat is introduced in R′₁ to evaporate the ammoniawhich is adsorbed on CaCl₂ at a temperature of 163° C. The heatliberated is transmitted to the reactor R₃ to liberate part of theammonia absorbed in the water, said liberation beginning when thetemperature in R₃ is 140° C., corresponding to the equilibriumtemperature for an ammonia concentration of 0.2 in the water. If theheat produced at 40° C. is useful, the installation operates for thesimultaneous production of cold and heat.

FIG. 13 shows the experimental Clapeyron diagram of an installation withtwo assemblies operating for the production of cold. In the twoassemblies, the working gas is ammonia and the reactors R′₁ and R′₃consequently operate alternatively as condenser and evaporator of NH₃.In the HP assembly, the reactor R₁ is the seat of a reaction of NH₃ withMgCl₂ according to the equation MgCl₂.2NH₃+NH₃⇄MgCl₂.6NH₃. In the LPassembly, the reactor is the seat of a reaction of NH₃ with NiCl₂according to the equation NiCl₂.2NH₃+NH₃⇄NiCl₂.6NH₃. During the coldproduction step, the ammonia is evaporated in R′₃ while producing coldat −5° C., the exothermic reaction in the nickel chloride occurs at 220°C. and the heat is transferred in R₁ for the desorption of the magnesiumchloride rich in ammonia, at 220° C., the liberated ammonia condensingin R′₁ at 30° C. while liberating heat. During the regeneration step,heat is introduced into R′₁ at 78° C. to evaporate NH₃ which is fixed onthe Mg chloride while liberating heat which is transferred in R₃ at 265°C. to decompose the nickel chloride rich in ammonia and the installationis again ready to produce cold. The reactor R′₃ is installed at theplace where the cold is used, the reactor R′₁ is installed at the placewhere the heat energy is available. The cold energy is thus transportedby a chemical method avoiding any heat losses.

1. A method for producing cold and/or heat at a given place using one ora plurality of thermal energy sources comprising a succession ofreversible processes between a gas and a liquid or a solid, which: isput into practice in an installation which comprises an HP assemblycomprising reactors R₁ and R′₁, an LP assembly comprising reactors R₃and R′₃, and possibly an IP assembly comprising reactors R₂ and R′₂, inwhich installation: each reactor R_(i) is the seat of a reversiblesorption alternatively producing and consuming the gas G_(i), eachreactor R′_(i) is the seat of a reversible process alternativelyproducing and consuming the gas G_(i), the respective sorbents and gasesin the reactors are selected so that, at a given pressure: the sorptionequilibrium temperature in the reactor R_(i) of an assembly is higherthan the equilibrium temperature of the reversible process in thereactor R′_(i) of the same assembly, the sorption equilibriumtemperature in the reactor R₁ is lower than that in R₃, and, ifapplicable, the sorption equilibrium temperature in R₂ is between theequilibrium temperatures in R₁ and R₃, the reactors R_(i) and R′_(i) ofan assembly are equipped with means for exchanging the gas G_(i), thereactors R_(i) are equipped with means for exchanging heat with eachother, the reactors are isolated from atmospheric pressure, and in whichthe thermal energy sources necessary for the operation of theinstallation supply the reactors R′_(i).
 2. The method as claimed inclaim 1, which comprises: a preliminary step in which the gas exchangemeans between two reactors of an assembly are closed and the respectivesorbents and gases are placed at ambient temperature in the reactors sothat the reactor R₁ of the HP assembly contains the sorbent in a formrich in gas (B₁,G₁), the reactor R′₁ is in a state to consume the gasG₁, the reactor R₃ of the LP assembly contains the sorbent in a formpoor in gas B3 and the corresponding reactor R′₃ is in a state to supplygas G₃, a step a) of the production of cold or heat, during which thegas exchange means are opened between the reactors R₃ and R′₃ on the onehand, the reactors R₁ and R′₁, and if applicable between the reactors R₂and R′₂, possibly after having raised the reactor R′₃ and if applicableR′₂ to a temperature higher than the normal temperature by the input ofheat energy, a step b) of regeneration during which the gas exchangemeans are opened between the reactors R₃ and R′₃ on the one hand, thereactors R₁ and R′₁, and if applicable between the reactors R₂ and R′₂,after having raised the reactor R′₁ and if applicable R′₂ to atemperature higher than the normal temperature by the input of heatenergy.
 3. The method as claimed in claim 1, for producing cold at agiven place using thermal energy sources located at another place,wherein: the respective gases and sorbents in the LP assembly (or the LPand IP assemblies) are selected so that, at the respective pressurewhich occurs in R′₃ (or in R′₃ and R′₂) after opening of the gasexchange means in the reactors, the equilibrium temperature of thereversible process in R′₃ (or in R′₃ and in R′₂) corresponds to thetemperature at which the production of cold is desired, during the stepa) of production, the gas exchange means are opened between the reactorswithout prior input of heat energy to the reactor R′₃ (or to thereactors R′₃ and R′₂).
 4. The method for producing cold as claimed inclaim 3, which is put into practice in an installation comprising the HPand LP assemblies, under the following conditions: during a preliminarystep, the gas transfer means between R₁ and R′₁ on the one hand, betweenR₃ and R′₃ on the other, are closed, the respective sorbents and gasesare introduced into the reactors so that the reactor R₁ of the HPassembly contains the sorbent in a form rich in gas (B₁,G₁), the reactorR′₁ is in a state to consume the gas G₁, the reactor R₃ of the LPassembly contains the sorbent in a form poor in gas B3 and thecorresponding reactor R′₃ is in a state to supply gas G₃, the respectivegases and sorbents in the LP assembly are selected so that, at therespective pressure which occurs in R′₃ after opening the gas exchangemeans, the equilibrium temperature of the reversible process in R′₃corresponds to the temperature at which the production of cold isdesired, during step a), the gas transfer means are opened between thereactors R₃ and R′₃ on the one hand, and between the reactors R₁ and R′₁on the other, which causes the production of cold in R′₃, during stepb), heat energy is supplied to R′₁ to raise it to a temperature higherthan the ambient temperature, the gas transfer means are then openedbetween the reactors R₃ and R′₃ on the one hand and between the reactorsR₁ and R′₁ on the other, thereby regenerating the installation.
 5. Themethod for producing cold as claimed in claim 3, which is put intopractice in an installation which comprises three HP, LP and IPassemblies respectively comprising the reactors R₁,R′₁, R₃,R′₃ andR₂,R′₂, under the following conditions: during a preliminary step, thegas exchange means are closed between the reactors R₁,R′₁, R₃,R′₃ andR₂,R′₂, the respective sorbents and gases are introduced into thereactors so that the reactor R₁ of the HP assembly contains the sorbentin a form rich in gas (B1,G1), the reactor R′₁ is in a state to consumethe gas G1, the reactors R₃ and R₂ of the LP and IP assemblies containtheir sorbent in a form poor in gas, respectively B3 and B2, and thereactors R′₃ and R′₂ are in a state to supply the respective gases G3and G2, the respective gases and sorbents in the LP and IP assembliesare selected so that, at the respective pressures which occur in R′₃ andR′₂ after opening the gas exchange means, the equilibrium temperaturesof the respectively reversible processes in R′₂ and R′₃ correspond tothe temperatures at which the production of cold is desired, during stepa), the gas exchange means are opened between the reactors R₁,R′₁,R₃,R′₃ and R₂,R′₂, thereby producing cold in R′₃ and in R′₂, during stepb), heat energy is added to R′₁, the gas exchange means are openedbetween the reactors R₁,R′₁, R₃,R′₃ and R₂,R′₂, thereby causing theregeneration of the installation.
 6. The method for producing cold asclaimed in claim 3, which is put into practice in an installation whichcomprises three HP, LP and IP assemblies respectively comprising thereactors R₁,R′₁, R₃,R′₃ and R₂,R′₂ under the following conditions:during a preliminary step, the gas exchange means are closed between thereactors R₁,R′₁, R₃,R′₃ and R₂,R′₂, the respective sorbents and gasesselected are introduced into the reactors so that the reactors R₁ and R₂contain their respective sorbent in a form rich in gas (B1,G1) and(B2,G2), the reactors R′₁ and R′₂ are in a state to consume therespective gas G1 and G2, the reactor R₃ contains the sorbent in a formpoor in gas B3, and the reactor R′₃ is in a state to supply the gas,during step a) in a first phase, the gas exchange means are openedbetween the reactors R₃,R′₃ on the one hand and between the reactorsR₂,R′₂ on the other, thereby producing cold in R′₃; in a second phase,the gas exchange means are opened between the reactors R₁,R′₁ on the onehand and the reactors R₂,R′₂ on the other, thereby producing cold inR′₂, during step b), heat energy is supplied to R′₁ to raise it to atemperature higher than the normal temperature, the gas transfer meansare then opened between the reactors R₁,R′₁ on the one hand and thereactors R₃,R′₃ on the other, thereby regenerating the installation. 7.The method for producing cold as claimed in claim 3, which is put intopractice in an installation which comprises three HP, LP and IPassemblies respectively comprising the reactors R₁,R′₁, R₃,R′₃ andR₂,R′₂, under the following conditions: during a preliminary step, thegas exchange means are closed between the reactors R₁,R′₁, R₃,R′₃ andR₂,R′₂, the respective sorbents and gases selected are introduced intothe reactors R_(i) and the reactors R′_(i) so that the reactors R₁ andR₂ contain their respective sorbent in a form rich in gas (B1,G1) and(B2,G2), the reactors R′₁ and R′₂ are in a state to consume therespective gas G1 and G2, the reactor R₃ contains the sorbent in a formpoor in gas B3 and the reactor R′₃ is in a state to supply the gas,during step a) the gas transfer means are opened between the reactorsR₃,R′₃ on the one hand and the reactors R₁,R′₁ on the other, therebyproducing cold in R′₃, during step b), in a first phase, heat energy isadded to R′₁ and communication is created between reactors R₁,R′₁ on theone hand and the reactors R₂,R′₂ on the other; in a second phase, heatenergy is added to R′₂, a connection is created between the reactorsR₂,R′₂ on the one hand and the reactors R₃,R′₃ on the other, therebycausing the regeneration of the installation.
 8. The method as claimedin claim 1 for producing heat at a temperature higher than that of aheat energy source, wherein, during step a) of production, heat energyis added to the installation by the reactor R′₃, and possibly by thereactor R′₂, before opening the gas exchange means between the reactorsR₃ and R′₃ and possibly between the reactors R₂ and R′₂.
 9. The methodas claimed in claim 8 for producing heat at a given place using heatenergy sources located at another place, wherein the heat source usedfor the regeneration step b) is the exergy of the heat produced atelevated temperature during step a).
 10. The method for producing heatas claimed in claim 8, which is put into practice in an installationwhich comprises an HP assembly comprising the reactors R₁ and R′₁ and anLP assembly comprising the reactors R₃ and R′₃, under the followingconditions: during a preliminary step, the gas transfer means between R₁and R′₁ on the one hand, between R₃ and R′₃ on the other, are closed,the respective sorbents and gases are introduced into the reactors sothat the reactor R₁ of the HP assembly contains the sorbent in a formrich in gas (B1,G1), the reactor R′₁ is in a state to consume the gasG1, the reactor R₃ of the LP assembly contains the sorbent in a formpoor in gas B3, and the corresponding reactor R′₃ is in a state tosupply gas G3, during step a), heat energy is added to R′₃ to raise itto a temperature higher than the normal temperature, the gas transfermeans are then opened between the reactors R₃ and R′₃ on the one hand,and the reactors R₁ and R′₁ on the other, thereby causing the productionof heat in R′₁, during step b), heat energy is added to R′₁ to raise itto a temperature higher than the normal temperature, the gas transfermeans are then opened between the reactors R₃ and R′₃ on the one hand,and the reactors R₁ and R′₁, thereby causing the regeneration of theinstallation.
 11. The method for producing heat as claimed in claim 8,which is put into practice in an installation which comprises three HP,LP and IP assemblies respectively comprising the reactors R₁,R′₁, R₃,R′₃and R₂,R′₂, under the following conditions: during a preliminary step,the gas exchange means are closed between the reactors R₁,R′₁, R₃,R′₃and R₂,R′₂, the respective sorbents and gases selected are introducedinto the reactors so that the reactor R₁ contains the sorbent in a formrich in gas (B1,G1), the reactor R′₁ is in a state to consume the gasG1, the reactors R₃ and R₂ contain their respective sorbent in a formpoor in gas B3 and B2, and the reactors R′₃ and R′₂ are in a state tosupply the respective gas G3 and G2, during step a), heat energy isadded to R′₃ and R′₂ to raise them to a temperature higher than theambient temperature, the gas exchange means are then opened between thereactors R₃,R′₃, the reactors R₂,R′₂, and the reactors R₁,R′₁, therebycausing the production of heat in R′₁, during step b), heat energy isadded to R′₁ to raise it to a temperature higher than the normaltemperature, the gas transfer means are then opened between the reactorsR₃,R′₃, the reactors R₂,R′₂ and the reactors R₁,R′₁, thereby causing theregeneration of the system.
 12. The method for producing heat as claimedin claim 8 which is put into practice in an installation which comprisesthree HP, LP and IP assemblies respectively comprising the reactorsR₁,R′₁, R₃,R′₃ and R₂,R′₂, under the following conditions: during apreliminary step: the gas transfer means are closed between thedifferent reactors, the respective sorbents and gases are introducedinto the reactors, at normal temperature, so that R₁ and R₂ containtheir respective sorbent in the state rich in gas (S1,G1) and (S2,G2),R₃ contains the sorbent in the state poor in gas, R′₁ and R′₂ are in astate to consume the gas G1 and the gas G2 respectively, and R′₃ is in astate to liberate the gas G3, during step a), heat energy is added toR′₃, the gas transfer means are then opened between the reactors R₃,R′₃on the one hand and the reactors R₁,R′₁ on the other, thereby causingthe production of heat in R′₁, during step b), in a first phase, heatenergy is added to R′₁, the gas transfer means are then opened betweenthe reactors R₁,R′₁ on the one hand and the reactors R₂,R′₂ on theother; in a second phase, heat energy is added to R′₂, the gas transfermeans are then opened between the reactors R₂,R′₂ on the one hand andthe reactors R₃,R′₃ on the other, thereby causing the regeneration ofthe system.
 13. The method for producing heat as claimed in claim 8,which is put into practice in an installation which comprises three HP,LP and IP assemblies respectively comprising the reactors R₁,R′₁, R₃,R′₃and R₂,R′₂, under the following conditions: during a preliminary step,the gas transfer means are closed between the different reactors, therespective sorbents and gases are introduced into the reactors, atnormal temperature, so that R₂ contains the sorbent in a state rich ingas (S2,G2), R₃ and R₁ contain their sorbent in a state poor in gasrespectively B3 and B1, R′₂ is in a state to consume the gas G2, and R′₃and R′₁ are in a state to liberate the gas G3 and G2 respectively,during step a) in a first phase, heat energy is added to R′₃, aconnection is created between the reactors R₃,R′₃ on the one hand, andthe reactors R₂,R′₂ on the other, thereby causing the production of heatin R′₂; in a second phase, heat energy is added to R′₂, a connection iscreated between the reactors R₁,R′₁ on the one hand, and the reactorsR₂,R′₂ on the other, thereby causing the production of heat in R′₁,during step b), heat energy is added to R′₁, the gas transfer means arethen opened between the reactors R₁,R′₁ on the one hand and the reactorsR₃,R′₃ on the other, thereby causing the regeneration of theinstallation.
 14. The method as claimed in claim 1, wherein thereversible process in the reactors R′_(i) is a liquid/gas phase change,an adsorption of a gas in a solid, an absorption of a gas in a liquid, achemical reaction between a gas and a solid or a liquid, or theformation of clathrate hydrates.
 15. The method as claimed in claim 1,wherein the reversible process in the reactors R_(i) is an adsorption ofa gas in a solid, an absorption of a gas in a liquid, a chemicalreaction between a gas and a solid or a liquid, or the formation ofclathrate hydrates.
 16. The method as claimed in claim 1, wherein thereversible processes in all the assemblies of the installation involvethe same gas.
 17. An installation for producing cold and/or heat, whichcomprises an HP assembly comprising the reactors R₁ and R′₁, an LPassembly comprising the reactors R₃ and R′₃ and possibly an IP assemblycomprising reactors R₂ and R′₂, wherein: each reactor R_(i) is the seatof a reversible sorption alternatively producing and consuming the gasG_(i), each reactor R′_(i) is the seat of a reversible processalternatively producing and consuming the gas G_(i), the reactants inthe reactors are selected so that, at a given pressure: the equilibriumtemperature of the sorption in the reactor R_(i) of an assembly ishigher than the equilibrium temperature of the reversible process in thereactor R′_(i) of the same assembly, the equilibrium temperature of thesorption in the reactor R₁ is lower than that in R₃, and if applicable,the equilibrium temperature of the sorption in R₂ is between theequilibrium temperatures in R₁ and R₃, the reactors R_(i) and R′_(i) ofan assembly are equipped with means to exchange the gas G_(i), thereactors R₁,R₃ and if applicable R₂ are equipped with means to exchangeheat between each other, the reactors are isolated from atmosphericpressure.
 18. The method as claimed in claim 2, for producing cold at agiven place using thermal energy sources located at another place,wherein: the respective gases and sorbents in the LP assembly (or the LPand IP assemblies) are selected so that, at the respective pressurewhich occurs in R′₃ (or in R′₃ and R′₂) after opening of the gasexchange means in the reactors, the equilibrium temperature of thereversible process in R′₃ (or in R′₃ and R′₂) corresponds to thetemperature at which the production of cold is desired, during the stepa) of production, the gas exchange means are opened between the reactorswithout prior input of heat energy to the reactor R′₃ (or to thereactors R′₃ and R′₂).
 19. The method as claimed in claim 2 forproducing heat at a temperature higher than that of a heat energysource, wherein, during step a) of production, heat energy is added tothe installation by the reactor R′₃, and possibly by the reactor R′₂,before opening the gas exchange means between the reactors R₃ and R′₃and possibly between the reactors R₂ and R′₂.
 20. The method forproducing cold as claimed in claim 9, which is put into practice in aninstallation which comprises three HP assembly comprising the reactorsR₁ and R′₁ and an LP assembly comprising the reactors R₃ and R′₃, underthe following conditions: during a preliminary step, the gas transfermeans between R₁ and R′₁ on the one hand, between R₃ and R′₃ on theother, are closed, the respective sorbents and gases are introduced intothe reactors so that the reactor R₁ of the HP assembly contains thesorbent in a form rich in gas (B1,G1), the reactor R′₁ is in a state toconsume the gas G1, the reactor R₃ of the LP assembly contains thesorbent in a form poor in gas B3, and the corresponding reactor R′₃ isin a state to supply gas G3, during step a), heat energy is added to R′₃to raise it to a temperature higher than the normal temperature, the gastransfer means are then opened between the reactors R₃ and R′₃ on theone hand, and the reactors R₁ and R′₁, on the other, thereby causing theproduction of heat in R′₁, during step b), heat energy is added to R′₁to raise it to a temperature higher than the normal temperature, the gastransfer means are then opened between the reactors R₃ and R′₃ on theone hand, and the reactors R₁ and R′₁, thereby causing the regenerationof the installation.
 21. The method for producing heat as claimed inclaim 9, which is put into practice in an installation which comprisesthree HP, LP and IP assemblies respectively comprising the reactorsR₁,R′₁, R₃,R′₃ and R₂,R′₂, under the following conditions: during apreliminary step, the gas exchange means are closed between the reactorsR₁,R′₁, R₃,R′₃ and R₂,R′₂, the respective sorbents and gases selectedare introduced into the reactors so that the reactor R₁ contains thesorbent in a form rich in gas (B1,G1), the reactor R′₁ is in a state toconsume the gas G1, the reactors R₃ and R₂ contain their respectivesorbent in a form poor in gas B3 and B2, and the reactors R′₃ and R′₂are in a state to supply the respective gas G3 and G2, during step a),heat energy is added to R′₃ and R′₂ to raise them to a temperaturehigher than the ambient temperature, the gas exchange means are thenopened between the reactors R₃,R′₃, the reactors R₂,R′₂, and thereactors R₁,R′₁, thereby causing the production of heat in R′₁, duringstep b), heat energy is added to R′₁ to raise it to a temperature higherthan the normal temperature, the gas transfer means are then openedbetween the reactors R₃,R′₃, the reactors R₂,R′₂ and the reactorsR₁,R′₁, thereby causing the regeneration of the system.
 22. The methodfor producing heat as claimed in claim 9, which is put into practice inan installation which comprises three HP, LP and IP assembliesrespectively comprising the reactors R₁,R′₁, R₃,R′₃ and R₂,R′₂, underthe following conditions: during a preliminary step: the gas transfermeans are closed between the different reactors, the respective sorbentsand gases are introduced into the reactors, at normal temperature, sothat R₁ and R₂ contain their respective sorbent in the state rich in gas(S1,G1) and (S2,G2), R₃ contains the sorbent in the state poor in gas,R′₁ and R′₂ are in a state to consume the gas G1 and the gas G2respectively, and R′₃ is in a state to liberate the gas G3, during stepa), heat energy is added to R′₃, the gas transfer means are then openedbetween the reactors R₃,R′₃ on the one hand and the reactors R₁,R′₁ onthe other, thereby causing the production of heat in R′₁, during stepb), in a first phase, heat energy is added to R′₁, the gas transfermeans are then opened between the reactors R₁,R′₁ on the one hand andthe reactors R₂,R′₂ on the other; in a second phase, heat energy isadded to R′₂, the gas transfer means are then opened between thereactors R₂,R′₂ on the one hand and the reactors R₃,R′₃ on the other,thereby causing the regeneration of the system.
 23. The method forproducing heat as claimed in claim 9, which is put into practice in aninstallation which comprises three HP, LP and IP assemblies respectivelycomprising the reactors R₁,R′₁, R₃,R′₃ and R₂,R′₂, under the followingconditions: during a preliminary step, the gas transfer means are closedbetween the different reactors, the respective sorbents and gases areintroduced into the reactors, at normal temperature, so that R₂ containsthe sorbent in a state rich in gas (S2,G2), R₃ and R₁ contain theirsorbent in a state poor in gas respectively B3 and B1, R′₂ is in a stateto consume the gas G2, and R′₃ and R′₁ are in a state to liberate thegas G3 and G2 respectively, during step a) in a first phase, heat energyis added to R′₃, a connection is created between the reactors R₃,R′₃ onthe one hand, and the reactors R₂,R′₂ on the other, thereby causing theproduction of heat in R′₂; in a second phase, heat energy is added toR′₂, a connection is created between the reactors R₁,R′₁ on the onehand, and the reactors R₂,R′₂ on the other, thereby causing theproduction of heat in R′₁, during step b), heat energy is added to R′₁,the gas transfer means are then opened between the reactors R₁,R′₁ onthe one hand and the reactors R₃,R′₃ on the other, thereby causing theregeneration of the installation.